SAN DIEGO -- Fifteen illegal immigrants aboard a rickety boat were rescued by U.S. authorities off the San Diego coast Wednesday morning after an apparent botched maritime smuggling attempt.

The dehydrated and sunburned passengers were taken off the 24-foot boat named "Seaulater" by federal authorities nearly a day and a half after leaving Rosarito Beach bound for Southern California, authorities said.

Authorities arrested two Mexican men in the group after the passengers identified them as being the smugglers. They allegedly charged $4,000 each for the passage, but the boat's engine died within 20 minutes of leaving the dock at Rosarito Beach about 10 p.m. Monday, said Lauren Mack, a spokeswoman for Immigration and Customs Enforcement.

The boat drifted 10 miles off the coast with no food or water supplies.

After their rescue, the immigrants didn't hesitate in identifying the traffickers.

"They are extremely angry with the smugglers," Mack said.

Including the two alleged smugglers, the passengers consisted of 14 Mexicans and one Salvadoran. They were rescued after a passing boat saw the vessel and contacted a private sea towing company. The towing company notified U.S. authorities.

The U.S. Coast Guard and Customs and Border Protection handled the rescue operation. The boat was in such bad shape that it barely made it to shore.

"It's sinking right now," Mack said Wednesday afternoon.

Investigations into immigrant-smuggling operations are often frustrated by immigrants' refusal to identify the smugglers. In this case, authorities said as many as five of the passengers offered to be witnesses. They will be allowed to stay in the country for the duration of the case.

The other immigrants are expected to be sent back to Mexico today. Immigration and Customs Enforcement is handling the investigation with assistance from the Border Patrol.

Maritime smuggling attempts are not uncommon in the spring and summer months, when vessels carrying illegal immigrants can blend in with the many recreational and fishing boats streaming in and out of San Diego Bay.

Recent months, however, have seen a spike in smugglers using rickety old boats that depart small ports in Mexico and come ashore on north San Diego County beaches, Mack said.

She said there have been at least 20 cases of boats being intercepted, sometimes with immigrants still aboard, sometimes empty -- left adrift or onshore. Two suspected smugglers have been arrested in previous incidents, she said.